Machine Comparison
Haas ST-20 vs Haas ST-20Y
Haas Automation vs Haas Automation · CNC Lathes
Summary
The Haas ST-20Y is the ST-20 lathe with Y-axis milling and a BMT-65 turret. Both have 8.4 in (213 mm) of X and 22.5 in (572 mm) of Z travel, 22.5 in (572 mm) of turning length, 2.5 in (64 mm) bar capacity, an 8.3 in (210 mm) chuck, a 6,000 rpm sub-spindle and the same 4,000 rpm, 20 hp (14.9 kW) spindle with 150 ft-lbf @ 500 rpm.
The ST-20 swings more, 13 in (330 mm) against 11.75 in (298 mm), and its listed rapids are 945 ipm (24 m/min) against 472 ipm (12 m/min). The ST-20Y carries a 12-station BMT-65 turret against a 12-station BOT turret and adds off-center milling. It weighs 10,480 lb (4,754 kg) against 8,820 lb (4,000 kg). Haas lists the ST-20 at US$77,995 and the ST-20Y at US$114,995.
Specifications Comparison
| Specification | Haas ST-20 | Haas ST-20Y |
|---|---|---|
| X-Axis Travel | 8.4 in (213 mm) | 8.4 in (213 mm) |
| Z-Axis Travel | 22.5 in (572 mm) | 22.5 in (572 mm) |
| Max Turning Diameter | 13 in (330 mm) ▲ | 11.75 in (298 mm) |
| Max Turning Length | 22.5 in (572 mm) | 22.5 in (572 mm) |
| Bar Capacity | 2.5 in (64 mm) | 2.5 in (64 mm) |
| Chuck Size | 8.3 in (210 mm) | 8.3 in (210 mm) |
| Max Spindle Speed | 4,000 rpm | 4,000 rpm |
| Spindle Power | 20 hp (14.9 kW) | 20 hp (14.9 kW) |
| Spindle Torque | 150 ft-lbf @ 500 rpm (203 N·m @ 500 rpm) | 150 ft-lbf @ 500 rpm (203 N·m @ 500 rpm) |
| Spindle Taper / Nose | A2-6 | A2-6 |
| Sub-Spindle Speed | 6,000 rpm | 6,000 rpm |
| Tool Capacity | 12 | 12 |
| Rapid Traverse | 945 ipm (24 m/min) ▲ | 472 ipm (12 m/min) |
| Machine Weight | 8,820 lb (4,000 kg) | 10,480 lb (4,754 kg) |
| Published List Price | US$77,995 | US$114,995 |
Advantages
Haas ST-20
- Lower published list price, US$77,995 against US$114,995
- 945 ipm (24 m/min) rapids against 472 ipm (12 m/min)
- 13 in (330 mm) max turning diameter against 11.75 in (298 mm)
Haas ST-20Y
- Y-axis for off-center cross-holes, flats, hexes and keyways
- 12-station BMT-65 turret for driven tooling
- Finishes milled features without a second-op VMC
Verdict
Buy the ST-20Y when your turned parts carry off-center features, such as cross-holes, flats or hexes, that now need a second operation on a mill; done-in-one machining is what the extra cost buys. For general turning of shafts and fittings up to 2.5 in (64 mm) bar with no milled features, the ST-20 does the same work on the same spindle, swings 13 in (330 mm) and lists at US$77,995.